Commentaria in Summam contra Gentiles, Liber II

The prooemium having been dispatched, and the division of the book having been set forth, Saint Thomas begins, according to the order of the division, to treat of the production of things ¹.

On this matter, however, he does two things: first, he treats of the very production of things with respect to the species and substance of that production; second, with respect to its quality, chapter XXII.

As to the first: since every production proceeds from some principle and terminates in something, he first treats of the principle of production; second, of the terminus, in chapter XV; third, of the production itself, in chapter XVI.

As to the first point: since "principle" signifies a relation to that which is from the principle, he does two things here as well. First, he determines concerning the principle itself; second, concerning God's relations to creatures, in chapter 11.

Because, however, power belongs only to those things that are principles of being, therefore, before he determines concerning power itself, which is the formal principle of production, he shows in this chapter that God is the principle of being for other things; but in the following chapter he begins to determine concerning power itself.

I. As far as the present chapter is concerned, then, this conclusion is laid down: It belongs to God to be the principle of esse and the cause for others.

Note, however, that there is added and cause, so that Saint Thomas may explain what he had said: principle of being. For form is a principle of being; yet it is not the productive cause of that of which it is the form, but is a formal principle. God, however, is a principle of being by way of an agent cause. And it is of such a principle that we speak here.

The conclusion, however, is proved from what was shown in the first book.

II. First. It was shown above, according to the mind of Aristotle, that there is some first agent cause, which is God. Now an efficient cause conduces its effects to esse. Therefore etc.

It must be noted that, although we say that forms concur so as to give esse, we do not use this manner of speaking of a form, as though the effect concurred toward esse. For this properly expresses the causality of the efficient cause, whose role is to reduce the effect from potency to act by producing the form from which the thing formally has esse. Now a form does not concur toward esse in an effect as though the esse of the form were something wholly extrinsic to the form, just as it is extrinsic to the agent qua agent; rather, esse is joined to the form itself as its formal effect, emanating from it through a certain natural resultant. The efficient cause, therefore, is said to concur with the effect toward esse because it gives to the effect, previously distant from esse, the form through which it exists in the nature of things.

Second. The first mover in any order of motions (namely, the essential order) is the cause of all the motions of that order. But many things are brought into being by the motions of the heavens. It was shown in the First Book that God is the first mover of that order of motions. Therefore God will be the cause of being for at least many things.

III. Third. God is a being in act. Therefore, etc. — The consequence is proved. To that which exists in act it belongs per se to produce some effect. Therefore every being in act is naturally apt to produce something existing in act. Therefore, etc. — The first consequence is evident: because what belongs per se to something is naturally present in it. — The antecedent is also manifest: because each agent acts insofar as it is in act.²**

Doubt is raised concerning the proposition immediately assumed: for it does not seem to establish the proposed conclusion. For although in order that something act, it is necessary that it be in act, it does not seem to follow from this that everything which is in act acts of itself and naturally: just as, although in order that something be capable of laughter, it must be an animal, it does not follow that everything which is an animal is capable of laughter. Therefore, although each thing acts insofar as it is in act, it does not follow that everything existing in act is active.

It is answered that, when it is said, Each thing acts according as it is in act, the according as specifies the account of acting: for just as heat is the form by which fire heats and is for itself the reason of heating, so universally form and act is for an agent the reason of acting, since every agent in acting makes something be in act. Now it is universally true that where there is the formal reason of something, that thing must be, and where that thing is, the formal reason must be: just as in whatever has heat, it must be capable of heating; and in everything capable of heating it is necessary that heat be present, either formally or virtually. If therefore being in act is for each agent the reason of its acting, it follows that every agent must be in act, and everything that is in act must be naturally active. Hence Saint Thomas said that being active with respect to an effect belongs to what exists of itself in act — that is, it belongs to a thing through its proper form by which it is in act; and consequently it belongs to it naturally, for those things that follow upon the form of a thing are natural.

To this objection it is answered that, although the esse of being risible belongs to nothing except what is an animal, still the esse of animal is not the reason why something is risible. For we do not say that something is risible insofar as it is an animal, but insofar as it is rational.

IV. Fourth. God is the most perfect being. Therefore, etc. — The consequence is proved: because a sign of perfection is found in lower things, as is said in Book IV of the Meteorology, namely that they can produce things like themselves. But God is ipsum esse in act. Therefore, etc.

It must be noted that, although creatures cannot be made like God according to one specific notion, they can nevertheless be made like him in the most common of all perfections, which is esse. Therefore Saint Thomas, from the fact that God can make something like himself, concludes that he can make something a being in act, just as he himself is act.

Fifth. God wills that his esse be communicated to others by way of likeness. Therefore he is the cause of being for others. — The antecedent was shown above in the First Book. — The consequence is proved, supposing that it belongs to the perfection of the will to be a principle of action and motion, as is said in III de Anima. The divine will is perfect. Therefore there is not lacking to it the power of communicating esse by way of likeness, if it wills to communicate it.

Note that Saint Thomas does not say absolutely that God wills to communicate His esse to others, but added, by way of likeness: so as to show that the mode of communication in creatures differs from the mode by which one divine Person communicates its esse to another Person. For there the same esse is communicated according to number; here, however, what is communicated is not the divine esse itself in itself, but a certain likeness of the divine esse, inasmuch as the esse of a creature is a certain participated likeness of it.

V. Finally. By the act that is in us, we can act not only in immanent actions, but also in transitive actions, by which we produce certain effects. Therefore, much more can God do this. Therefore He can be the cause of being to others. — The inference is proved: because the more perfect the principle of an action is, the further it can extend its action into more things and toward more remote ends. Therefore, if the act existing in us, which is mixed with potency, can act not only in an immanent action but also in one that passes outward into external things, much more will the act with which no potency is mixed be able to do so, as is God.

It must first be noted that no act existing in a creature is one that is not compared to esse as potency to act, since esse is the actuality of all things. On account of this Saint Thomas says that act in us is mixed with potency.

It must be noted, secondly, that a twofold act is attributed to the intellect and the will: one immanent, namely understanding and willing absolutely; the other transient, which is to move, whether by way of a commanding power or by way of a power that immediately elicits the motion; for it makes no difference, as far as the matter at hand is concerned, which of these we say. Therefore, when Saint Thomas says that by the act existing in us we can act in an immanent and a transient action, by the name act existing in us we can understand the will and the intellect: so that there may be a correspondence and likeness between us and God, though an imperfect one; for in us and in God both of these acts are attributed to the will and the intellect. We can also understand the soul itself, which by its diverse powers can exercise these diverse operations. The second seems better: because Saint Thomas is not speaking here of the act of moving the conjoined body locally, but of the act of some extrinsic producer, which is certainly exercised by some bodily member. But then, although there is some likeness between us and God with respect to these acts, there is nevertheless a dissimilitude in this, that we elicit these actions through diverse proximate principles, whereas God does so through a single principle, which is his will. This happens on account of his very perfection, from which it follows that what exists in creatures as distinct, he himself possesses unitedly and indivisibly.

This conclusion is finally confirmed by the authority of Job, chapter 5: "Who does great things."